Vehicle telematics service providers, also referred to herein as call centers, offer their customers a variety of services, including safety, navigation, and vehicle diagnostic services. The services can be delivered to the customer via an installed telematics unit within the customer's vehicle. For diagnostic assistance, such as when the driver is presented with a warning light, sound, or vehicle information center text message, these telematics services allow the driver to initiate a call into the call center and inquire as to the source and possible fix of the problem. In newer systems, the driver can identify the particular light, sound, or message to the advisor at the call center and, in response, the advisor can remotely initiate an over-the-air diagnostic test that covers all of the available vehicle system modules (i.e., all of the modules accessible to the vehicle's telematics unit that is in communication with the call center). The particular test used is somewhat dependent on the description that the driver provides to the advisor.